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Modding LED case lighting. how would YOU do it?

Discussion in 'Modding' started by Avatar28, 29 Jan 2003.

  1. Avatar28

    Avatar28 What's a Dremel?

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    In order to keep a theme going in my case, I'm wanting to use LEDs to illuminate it, at least for the blue (CCFLs are the wrong color for me). I was considering trying to make some sort of array of lights going around the edges of my case (think like christmas tree lights). I've also thought about doing it with UV ones as well.

    Aside from the light color, another reason I would like to go with LEDs is for the fact that I can dim the brightness of them.

    Has anyone done this before or have any suggestions from working with lots of LEDs? I think it will be a really awesome mod if I can pull it off.
     
  2. supernismoboy

    supernismoboy What's a Dremel?

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    what about neon string, thats sometimes a better colour than cold cathodes? just a thought :)
     
  3. chambochae

    chambochae What's a Dremel?

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    a ultrabright blue led is pretty bright. bright enuff that it will shine on the opposite wall of my bedroom during the day. I reckon you'd only need a few.
     
  4. ZapWizard

    ZapWizard Enter the Mod Matrix

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    Ok for LED lighting you need to know a few things about your LED's

    First off the Voltage Drop.
    If the LED's voltage drop is 2.4volts, you run up to 5 LED's off of 12 volts, in series, with one resistor.
    12/2.4=5

    Then you need to know the current rating.
    DONT run the LED at the Max rating (Usualy 30mA)
    Most Bright LED's run at 20mA

    If you connect the LED's in series the Amps never change.
    If you run the LED's in parallel then the Amps add together.

    YOU ALLWAYS Need a resistor.
    One resistor per series of LED's
    One resistor Per LED if ran in Parallel
    Use the Bit-Tech LED calculator for find the value of resistor.
    http://www.bit-tech.net/article/68/

    For example:
    5 LED's in Series: would consume all 12 volts
    You would need a very small resistor of 10ohms to limit the current. This is because the entire 12volts has been consumed by the LED's. There is no voltage that the Resistor has to absorb.
    The total current would be 20mA
    Code:
    +12volts----/\/\/--->|------>|------>|------>|------>|---Ground
    
    BUT if you run the LED's in parallel then the situation is different
    5 LED's in Parallel would each consume 2.4volts, Each LED would need a resistor of 560ohms in order to absorbe the extra 9.6volts left over. The total current would be 100mA (20x5)
    Code:
                     |---/\/\/---->|---|
                     |---/\/\/---->|---|
                     +12volts--+---/\/\/---->|---+---Ground
                     |---/\/\/---->|---|
                     |---/\/\/---->|---|
    
    So if you want a LOT of LED's you need to use a combo of Parallel and Series. This makes sure Each LED is as bright as possible, but without wasting any power on the resistors.
     
  5. RAM Z

    RAM Z What's a Dremel?

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  6. wedgius

    wedgius What's a Dremel?

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    :eeek:

    Too bad GaN LEDs are still expensive. :sigh:
     
  7. Kargin

    Kargin Overdose . . .

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    OMG FAP


    I have the green pack of these, and they are BRIGHT. I think each LED is rated at about 10,000 MCD. :D

    I caused me, both my parents, and my one friend to scream in agony as they accidentally lined up with their eyes.

    I cna light my entire 8' x 10' room with one of these.

    They just polug right into your molex, so if electronics isn't your thing. . . . . :D

    Kinda pricey, but that's also Canadian dollars mind you. I'm sure most decent mod shoips carry something like them :worried: Don't they?
     
  8. Avatar28

    Avatar28 What's a Dremel?

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    Well, part of the whole idea behind the LED lighting is to be able to spread the light more evenly throughout the case. I know that, ideally, you should have one resistor per LED or LED series if they're in parallel, but I'm not entirely certain how well that will work with having a pot for the dimming. I could, I suppose, have it so that when the pot's at 0, they're all set for max brightness and as I crank up the pot they dim down until they're basically off.

    I've got 100 blue 2000mcd LEDs that I got off ebay for $10.50 +shipping. I just don't know how good they're going to be or how wide the viewing angle will be. If they're really narrow beam, that's probably going to creat problems.

    I haven't ordered any UV ones yet. I've got an email in to a guy who sells those and he's got two types, but one type is about 8-10 times the price of the others.
     
  9. Dark_Blender

    Dark_Blender What's a Dremel?

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    LEDs have a pretty small viewing angle so with LEDs that bright, you will have lil blue circles all over your puter. LED's light up massively:yawn:
     
  10. wedgius

    wedgius What's a Dremel?

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    With that bar of LEDs, it looks like you could just sand the tube down a bit and spray it with window-frosting spray (a la Macro Black, or at least its power button). That should diffuse the light enough. :)
     
  11. Avatar28

    Avatar28 What's a Dremel?

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    Yeah, I'm kinda wondering if I were to sand the leds slightly to rough them up if it would help with the dispersion. I also considered aiming them not directly at the board, but other directions so that it's more reflected. I guess I may have to try it somewhat. There may be something else I could do too to make it work. Like make my own covered lightbar with lots of LEDs.
     
  12. SteveyG

    SteveyG Electromodder

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    This is how my PC looks with only LED illumination. This is with the LED's operating and half brightness.

    The camera is not lying, its very very bright. The light is much more intense than any CCFL.

    They're dimmable using a PWM controller that I made which is housed behind the LCD.

    [​IMG]
    [​IMG]
     
  13. Seth

    Seth What's a Dremel?

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    steve: where did you get your leds? and what mcd rating are thoes sucksers?
    one last question. how did you wire all of thoes up it might help out our friend that made this thread.
     
  14. linear

    linear Minimodder

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    Okay, it looks like there's a good amount of interest in LED lighting that's packaged.

    Stay tuned, I have something for you....
     
  15. SteveyG

    SteveyG Electromodder

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    I used LED's from Rapid Electronics. They're 2200mcd@20mA.

    To wire them up I positioned all the LED's where I wanted them, cut some thin wire to length and then wired three LED's in series at a time along with the correct resistor. Then all these strings were wired in parallel and connected to a PWM controller to allow them to be dimmed.

    I think there's 34 LED's in total. 30 inside and 4 lighting up the front panel. The Coolermaster LED fans have their LED's connected to the PWM controller aswell with the motor control on a seperate channel.
     
  16. zackerouac

    zackerouac bring it

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    thats so wrong :wallbash:
     
  17. Avatar28

    Avatar28 What's a Dremel?

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    OMG!!! That is SOOOO freaking awesome. *wiping the drool off his chin*

    Can you give me any idea how you made the PWM controller and how you actually adjust it?

    This is basically the case I'm getting, except that mine has the fan on top (which you can actually see in some shots of this).

    /edit. PLEASE edit images out of your quotes, Thanks -ZapWizard
     
  18. SteveyG

    SteveyG Electromodder

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    I've built several different types of PWM controller. For dimming of LED's they all work equally well. I used the SG3525 in this application since I had some spare. There's a datasheet available from the ST website. You can also build a much simpler PWM controller just using a nand gate oscillator.

    Its not all that necessary to use a PWM controller for dimming LED's, but I personally dislike using high power variable resistors in almost any application, and a voltage regulator wouldn't be much use for dimming LED's because if after turning the knob about 1/6 of a turn the output voltage would be lower than the forward voltage of the LED's and they'd all cease to light. PWM provides controllable dimming over the whole turn of the potentiometer, and it runs cool. The heatsink doesn't even get warm.

    Anyway, here's the datasheet.
     
  19. Nexxo

    Nexxo * Prefab Sprout – The King of Rock 'n' Roll

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    ... or you could use one of :these:...

    [​IMG]

    They're LEDs, really --Lumileds in a nice little package. Lumileds are the Big Arnies of the LED world. I mean, insanely big, bright muthas. Just the job for your case: one is sufficient to light the entire insides.
     
  20. pranks7er

    pranks7er mange tout

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    im considering using ultrabright yellow leds for a light effet in my case, rem each led will need protected by a correct value resistor maplin.co.uk is a good electronics shop.

    has any one used yellow low voltage halogens for the same effect?
     

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